Electronic system, components and method for tracking files

ABSTRACT

A file tracking system including a processor, which maintains and interfaces with a database, a plurality of file folder retainers, and a plurality of file folders. The file tracking system actively maintains and updates the database, which includes file information, file location, and unique file address for the plurality of files, by providing interactive communication between the processor, the folder retainers, and the file folders. Each file folder may include an indicator light, such as an LED, which a user may cause to blink when trying to locating the file folder at a location accessed from the database.

BACKGROUND OF THE INVENTION

In general, the present invention relates to an electronic system,hardware, and method for tracking the location of files and theircontainers. More specifically, the present invention relates to anelectronic file tracking system that maintains a database identifyingeach file and its current location by interactive communication betweena computer processor and the file folders. The invention is particularlyadapted for use with office furniture.

In a typical office environment, files are normally stored in variousfile cabinets located throughout the office. Each file cabinet or groupof file cabinets stores files belonging to a particular category. Thesefiles are typically organized in an alphabetical or numerical orderwithin the drawers of the file cabinet or group of file cabinets. Filesmay also be stored on or in various shelving units, trays, boxes, worksurfaces, bins, compartments, tables, desk drawers, or carts. In orderto make these files accessible to all office personnel, the files mustbe stored in an organized manner. Office personnel expend a substantialamount of time retrieving files, replacing files back into the filecabinets, and maintaining the organization of the files.

When someone wishes to obtain a particular file, he or she mustdetermine in which office, which file cabinet, and which drawer of thefile cabinet the file is supposed to be located. If the person lookingfor the file does not know the location of the file first hand, he orshe must make inquiries to the other employees or check a manuallymaintained listing of the file organization to locate the file. Oncethis person identifies where the file is suppose to be located, theperson must search through the numerous files stored in the drawer todetermine if the file is actually located in the drawer. In searchingthrough the file cabinet drawer, this person may discover that the fileis not located where it was supposed to be. The person must then againinquire about the office to determine if someone else has the file and,if no one else has the file, this person must search through other filedrawers to determine if the file is misfiled or lost. Active files tendto become stacked on the desktops of the employees most recently usingthose particular files, leading to poor accessibility for others.Clearly, tracking down a file may consume a significant portion of anemployee's time and any time spent looking for or reorganizing files isan inefficient use of that employee's time.

To maintain an organized system, when someone must add a number of newfiles to a particular drawer of a file cabinet that is already filled tocapacity, he or she must shift those files in the back of the drawer toanother drawer, which may also be filled to capacity. Further, whenevera sequential ordering scheme is used to organize files, even frequentlyaccessed files may be dispersed throughout a number of drawers ratherthan in the front of a single file drawer where the frequently accessedfiles would be more easily accessible.

The above problems are particularly prevalent in hospitals, doctorsoffices, law offices, government agencies, and anywhere else where largeamounts of printed documents or other media are handled and maintained.

One approach that was developed to alleviate some of the above problemsin tracking files is to provide a bar code label on each file folder andto maintain a database correlating the bar code I.D. of the file and itsrelative location. In order to accurately maintain the file locations inthe database, bar code readers are placed about the office for employeesto scan the bar code and enter a new location whenever the employeesmove a file from one location to another.

The problem with this approach is its reliance upon the employees totake the time to scan the bar code and enter user and locationidentification information into the database every time an employeepulls a file out of a file drawer or off a shelf. Furthermore, thedatabase may only identify the general location of the file, which maybe a location where many other files are also located. Thus, althoughsomeone looking for a file may know its general location, this personmay spend considerable time trying to locate the file amongst thenumerous other files, particularly if the file is misfiled.Additionally, not all possible locations and potential users of thefiles may be identified within the database. Thus, the database may notaccurately reflect the exact location of a file.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made to overcome the aboveproblems of the conventional filing system. The file tracking system ofthe present invention automatically determines when a file has beenremoved from its previous location, when it is returned, and determineswhen a new file has been added to the system. Additionally, the filetracking system of the present invention allows users to easily andaccurately identify the exact location of a file by having a processorcommunicate with a device carried by the file folders and activate anindicator, such as a light, on the file folders and/or file cabinets inresponse to a signal sent by the processor. Thus, the present inventionrequires minimal human interaction to maintain an accurate databaseidentifying the location of the files while permitting both random andordered filing of the file folders. Moreover, the file tracking systemof the present invention may be inexpensively and readily implemented inexisting office furniture.

Additional features and advantages of the invention will be set forth inpart in the description which follows and in part will be apparent fromthe description, or may be learned by practice of the invention.

The features and advantages of the invention may be realized andobtained by means of the instrumentalities and combinations particularlypointed out in the written description and claims hereof as well as theappended drawings.

To achieve these and other advantages, and in accordance with thepurpose of the invention as embodied and broadly described herein, thefile tracking system of this invention includes a database formaintaining at least file identity, file location, and unique fileaddress for a plurality of files, a processor for interfacing with thedatabase and issuing control signals, a bus connected to the processor,a folder retainer connected to the processor by the bus, a plurality offile folders, each file folder including an addressable device adaptedto be electrically connected to the bus when the file folder is placedin the folder retainer. Each folder may include an indicator which isactivated when the addressable device receives a control signal from theprocessor including the unique address corresponding to the file folder.The database may additionally store the following: access information,which may be used to prevent individuals from accessing certain filefolders; retention information, which may be used to determine thelength of time since the file folder was last accessed in order todetermine whether the file may be purged; classification information,which may indicate any classification groups the file folder isassociated with; access history, which may indicate who checked out thefile folder and when the file folder was checked in or out; key wordlists, which list certain key words that describe or may be found in thefile; and location history information, which may indicate the locationsand dates at which the file folder has been located over a period oftime.

The above features and advantages may also be attained by using the filecabinet of the present invention in a file tracking system. The filecabinet of the present invention includes a plurality of file drawers,at least one file drawer including a first conductor for providingcontrol signals a file folder when the file folder is placed in the filedrawer, the control signals being provided by the file tracking system,and a second conductor for providing a return path from the file folderplaced in the file drawer.

Additionally, the advantages of the present invention may be attained byusing a file folder of the present invention in a file tracking system.The file folder of the present invention includes at least one surface,an addressable device carried by the file folder and having a uniqueaddress, a first conductor on the surface electrically coupled to theaddressable device for providing control signals to the addressabledevice when the file folder is placed in a folder retainer, the firstconductor adapted to communicatively couple to a processor of the filetracking system, the control signals being provided by the processor,and a second conductor on the surface for providing a return path fromthe addressable device.

These and other features, objects, and benefits of the invention will berecognized by those who practice the invention and by those skilled inthe art, from the specification, the claims, and the drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings which are incorporated in, and constitute apart of, this Specification illustrate several embodiments of theinvention and, together with the description, serve to explain theobjects, advantages, and principles of the invention.

FIG. 1 is a pictorial view of a file tracking system constructed inaccordance with a first embodiment of the present invention;

FIG. 2 is a block diagram illustrating the hierarchy of the filetracking system of the present invention;

FIG. 3 is an electrical schematic view illustrating the electricalconnections of a portion of the file tracking system shown in FIG. 1;

FIG. 4 is an electrical schematic view of an addressable switch whichmay be used in the file tracking system of the present invention;

FIG. 5 is a perspective view of a file folder in electrical contact witha bus conductor according to a first implementation in the file trackingsystem of the present invention;

FIG. 6 is a perspective view of a file folder and a bus conductoraccording to a second implementation in the file tracking system of thepresent invention;

FIG. 7 is a perspective view of a hanging file folder in electricalcontact with a bus conductor according to a third implementation in thefile tracking system of the present invention;

FIG. 8 is a graphic view of a main user interface window of the filetracking system of the present invention;

FIG. 9 is a graphic representation of a debug window of the filetracking system of the present invention;

FIG. 10 is a graphic representation of a Get Number dialog box of thefile tracking system of the present invention;

FIG. 11 is a flow chart illustrating the polling operation of the filetracking system of the present invention;

FIG. 12 is flow chart showing the device scanning operation of asubroutine executed by the file tracking system of the presentinvention;

FIG. 13 is a flow chart showing the indicator light scanning operationof the file tracking system of the present invention;

FIG. 14 is a pictorial view of a file tracking system constructed inaccordance with a second embodiment of the present invention; and

FIG. 15 is a pictorial view of a file tracking system constructed inaccordance with a third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings.

The exemplary embodiment of the file tracking system of the presentinvention is shown in FIG. 1 and is designated generally by thereference numeral 10. As used throughout this description of theinvention and in the following claims the term "media" includes paper,film, X-ray film, magazines, books, photographs, microfiche, video andaudio tapes, models, exhibits, or anything else retained and filed. Theterm "file folders" refers to any type of structure for containing mediaincluding bi-fold, side-tab, expandable, and tri-fold file folders, andmay further include various types of binders, jackets, envelopes, boxes,holders, cartons or the like. The term "files" as used herein includesthe file folder and all media inside. The term "folder retainers" refersto various numbers of, and/or combinations of, file trays, filecabinets, shelving units, desks, furniture drawers, packing boxes,archive tubs, wall-mounted or countertop file racks, bins, carts, pads,mats, desk tops, countertops, any work surface on which file folders arecommonly stacked or placed, or any other structure for holding filefolders. A "file locating device" broadly includes any device that wouldassist a user to locate a file. An "annunciator" is a file locatingdevice that audibly and/or visually announces the location of a file,and includes audible alarms, such as beepers, and visual indicators,such as light emitting diodes (LEDs). Additionally, other types ofannunciators or, as more broadly defined herein, file locating devices,such as an audible alarm, may supplement or replace the visual indicatorlights used in the file tracking system.

In general, file tracking system 10 includes a processor 20 and aplurality of folder retainers. For purposes of example, FIG. 1 shows afile tray 40, a file cabinet 50, a shelving unit 60, and a desk 85although any of the above defined folder retainers may be used invarious numbers and combinations.

A bus 30 communicatively couples processor 20 with the folder retainers.Each folder retainer includes bus conductors 80 for electricallycontacting one or more file folders 70. Bus 30 preferably includes twolines. One for providing control signals to file folders 70 and anotherfor providing a return. Although the preferred embodiment utilizes twolines, bus 30 may be implemented in any bus using any number of physicalor virtual, multiplexed lines. Bus conductors 80 may be included on asurface of a file retainer such as a file drawer, or embedded within aworking surface, such as a desktop, countertop, shelf, or tray, tocreate a file retainer location thereon.

Processor 20 includes a display 22 and an input device 25, such as akeyboard. Preferably, processor 20 is a personal computer. As will beexplained in greater detail below, processor 20 maintains and interfaceswith a database under the direction of an operating program thatinstructs processor 20 to actively communicate with the folder retainersand the file folders 70 via bus 30. In this manner, processor 20 mayupdate the database and maintain accurate information on the location offile folders 70 placed in the system. The database used may be anycommercially available ANSI SQL compatible database, such as MicrosoftAccess™ database.

A tray 40, which is useful in the file tracking system 10 of the presentinvention, may be formed of a conventional file tray modified to includea bus conductor 80 having at least two conductive strips (42, 43), anindicator light 45, such as a light emitting diode (LED), and anaddressable switch 100 (FIG. 4), which is connected between theconductive strips and indicator light 45. Preferably, the conductivestrips include at least one ground conductor 42 and at least one controlconductor 43 connected to bus 30. As will be described in greaterdetailed below, tray 40 provides a communication link between filefolders 70, which are placed thereon to processor 20 whereby processor20 can track the location of file folders 70 placed on file tray 40 andcan selectively light indicator light 45 on tray 40 and any indicatorlight 75 on file folders 70.

File cabinet 50 includes a plurality of drawers 54a-54c, each of whichincludes an indicator light 55a-55c on an outer drawer face. Each drawer54a-54c further includes a bus conductor 80 having at least one groundconductor 52 and a control conductor 53, which contact the conductivestrips of file folders 70, and an addressable drawer switch 100 (FIG.4), which is connected between ground conductor 52, control conductor53, and indicator light 55a-55c. File cabinet 50 may optionally includea branch indicator 95 (FIG. 3) associated with a branch control point 92(FIG. 2) and having a unique cabinet address and an indicator light 51that can be lit whenever processor 20 transmits a control signalincluding the unique cabinet address of the addressable cabinet switch.

Shelving unit 60 includes at least one shelf 61a-61b, which includes abus conductor 80 having at least one ground conductor 62 and a controlconductor 63 for contacting the conductive strips of file folders 70.Shelving unit 60 also preferably includes an addressable switch 100having a unique address and an indicator light 65, which can be litwhenever processor 20 transmits a control signal including the uniqueaddress of the addressable switch.

Desk 85 includes at least one drawer 86a, 86b which includes a busconductor 80 therein and an indicator 87a, 87b on an outer face thereof.In addition, desk 85 may include a bus conductor 80 embedded in a worksurface thereof. Further, a mat 88 having a bus conductor 80 embeddedtherein may be placed on the top of desk 85 or any other working surfaceof an article of furniture.

FIG. 2 illustrates a typical system hierarchy employed when severalbranch connections exist in the system. A user's work area 90 mayinclude, for example, a processor 20 and a plurality of file cabinets50. Because each file cabinet 50 includes a plurality of drawers54a-54c, which, in turn, contain a plurality of file folders 70, filetracking system 10 preferably utilizes the hierarchy shown in FIG. 2 toseparately activate a single branch at a time. To enable a single branchto be activated at a time, file tracking system 10 preferably includes aplurality of branch control points 92, 92', which may be individuallyactivated to permit access to the branch controlled by the branchcontrol point 92. Thus, to access file folders 70 in a drawer 54a offile cabinet 50a, processor 20 transmits a control signal to the branchcontrol point 92 for the file cabinet 50a such that processor 20 may nowtransmit a control signal to the branch control point 92' for drawer54a. After processor 20 transmits a control signal to branch controlpoint 92 for cabinet 50a, processor 20 transmits a control signal to thebranch control point 92' for drawer 54a to activate the bus conductors80 located in drawer 54a thereby allowing processor 20 to communicatewith file folders 70 included in file drawer 54a. Alternatively, aprocessor 20 that is located outside user's work area 90 may access filefolders 70 within user's work area 90 by transmitting control signalsthrough a network 91. File tracking system 10 may further include aserial port adaptor or secondary processor 27, which is connected toreceive control signals from a serial port of processor 20, convert thereceived control signals to a format appropriate for a single pair bus,and distribute the control signals to the correct file cabinet 50 orother folder retainer connected to the system.

FIG. 3 shows an exemplary electrical schematic of the connectionsbetween processor 20 and file folders 70. As shown in FIG. 3, bus 30includes a control line 31 and a ground line 32. Bus 30 is preferably asingle pair bus. In the hierarchical arrangement shown in FIG. 3, branchcontrol point switch assemblies 93a and 93b represent control points foractivating the bus conductors 80 of two different file drawers 54 of afile cabinet 50. Although only one file folder (70a, 70b) is shown foreach file drawer 54, each file drawer 54 will typically have a pluralityof file folders 70 contacting its bus connector 80.

Each file folder 70 preferably includes a folder indicator light 75 andan addressable folder switch 76 having a unique address associatedtherewith. Alternatively, each folder may include an addressable devicewhen an indicator is not employed such that each folder has a unique IDtag that may be communicated to processor 20. Although the file folders70 are illustrated as bi-fold file folders, as stated above, the filefolders may be any type of file folder as previously defined.

FIG. 4 shows the general structure of an addressable switch 100 usefulin the file tracking system of the present invention. Addressable switch100 includes a load transistor 101 having a gate 102, a source servingas a load terminal 103, and a drain serving as a ground terminal 104.Addressable switch 100 further includes a digital control device 105connected between gate 102 and a control terminal 106. Digital controldevice 105 includes a read only memory (ROM) 108 in which the uniqueaddress of addressable switch 100 is stored.

Digital control device 105 receives control signals at control terminal106. These control signals include an address and a command. Whendigital control device 105 senses a control signal at control terminal106, digital control device 105 compares the address in the receivedcontrol signal to the unique address stored in ROM 108. If the addresscontained in the control signal is not the same as the unique addressstored in ROM 108, digital control device 105 awaits further controlsignals. If, on the other hand, the address contained in the controlsignal is the same as the unique address stored in ROM 108, digitalcontrol device 105 executes the command contained in the receivedcontrol signal or contained in a subsequently transmitted controlsignal.

In the context of the present invention, addressable switch 100 mayperform various tasks in response to an appropriate command received atcontrol terminal 106. For example, digital control device 105 may changethe state of load transistor 101 between conductive and nonconductivestates by controlling the voltage applied to gate 102. Additionally,digital control device 105 may transmit a reply signal over controlterminal 106 indicating the state of load transistor 101 or the uniqueaddress stored in ROM 108. By transmitting the state of load transistor101, digital control device 105 may transmit the status of an attachedindicator light. Preferably, digital control device 105 derives it powerentirely from control line 31 by storing energy in a capacitor (notshown) when control terminal 106 is in a high logic state. An example ofan addressable switch 100 that may be used in the file tracking systemof the present invention is the DS2405 addressable switch available fromDallas Semiconductor, in Dallas, Tex.

Referring again to FIG. 3, branch control points 92a, 92b, . . . 92neach include at least one branch control point switch assembly 93a, 93b,. . . 93n including a branch control addressable switch 94a, 94b, . . .94n having a unique address associated therewith. Branch control point92a may also include a branch indicator 95a, which includes a branchindictor light 96a, such as an LED, and a branch indicator addressableswitch 97a having a unique address associated therewith to permitindependent control of branch indicator light 96a by processor 20.

To communicate with file folder 70a located in a particular drawer 54a,processor 20 transmits a control signal over control line 31 via serialport adaptor 27 to control terminals 106 of all branch controladdressable switches 94a, 94b, . . . 94n connected to ground line 32.The transmitted control signal includes the unique address associatedwith branch control addressable switch 94a associated with drawer 54awith which communication is desired. The control signal also includes acommand instructing this branch control addressable switch 94a to changeto a conductive state thereby providing a connection between ground line32 and addressable folder switch 76a. Subsequently, processor 20 maytransmit control signals individually to addressable folder switch 76aby including the unique address associated therewith. Thus, processor 20may illuminate folder indicator light 75a of any specified file folderwithin a specified drawer 54a. Additionally, processor 20 may obtaininformation from addressable folder switches 76a, 76b, . . . 76n througha later described, deterministic process to determine the unique addressstored in ROM 108 of each of addressable folder switches 76a, 76b, . . .76n. Processor 20 may also illuminate branch indicator light 96a byfirst transmitting a control signal including the unique address ofbranch control addressable switch 94a and subsequently transmitting acontrol signal including the unique address of branch indicatoraddressable switch 97a. By providing a branch indicator light 96a on afolder retainer such as a file drawer 54a, a file tray 40, or a shelvingunit 60, one can quickly determine in which folder retainer a selectedfile folder 70 is located by looking for the folder retainer with theilluminated branch indicator light 96.

In the preferred embodiment, each file folder 70 has an addressableswitch having a unique address associated therewith in any given systeminstallation. In some applications, multiple file folders 70 couldintentionally have identical addresses corresponding to files related orgrouped in some fashion. Further, an inadvertent duplication ofaddresses could result in any installation from a finite number ofaddresses in a mass produced, manufacturing environment. In all suchsituations, unique addresses are still present as envisioned herein.

The manner in which contact can be made between the conductive strips ona file folder 70 and the conductive rails of a bus conductor 80 will nowbe described with reference to FIGS. 5-7.

Bus conductors 80a, 80b, 80c preferably include at least one groundconductive rail 82a, 82b, 82c, a control conductive rail 83a, 83b, 83c,and a support 84a, 84b, 84c for supporting the conductive rails. Support84a, 84b, 84c preferably is formed of an electrically insulatingmaterial and supports the conductive rails in parallel with one another.Bus conductor 80a-80c may be formed as an integral part of a folderretainer or, alternatively, may be formed as a separate element whichmay be added to an existing folder retainer. As shown in FIG. 5, busconductor 80a may be implemented in a vertically spaced, horizontallyextending manner to provide contact along a vertical side, end, or backsurface of a folder retainer. Thus, using bus conductor 80a, contact maybe provided along the back of a shelving unit or bookcase or along theside of a file or desk drawer. Alternatively, as shown in FIG. 6, busconductor 80b may be implemented such that contact is provided in ahorizontally spaced, horizontally extending manner along a horizontal orbottom surface of a folder retainer. Horizontally extending busconductor 80b is advantageous in that contact with the file folders isaided by gravitational forces and that contact may be made with eitherthe edges of file folders vertically stacked thereon or with the largeexterior surfaces of file folders laid flat thereon. Moreover, as shownin FIG. 7, bus conductor 80c may be implemented as a support rail in afile drawer 54 upon which hanging file folders 70c may be suspended. Insuch an implementation, file folder 70c does not require conductivestrips, but rather a file folder indicator light assembly 71 is providedhaving a contact 78 for contacting control conductive rail 83c and awire 77 connected to file folder hanger extension 74, which in turncontacts ground conductive rail 82c. However, hanging file folders 70cmay still have such conductive strips to provide stackability andredundant contact through adjacent file folders as is later described.

Bus conductors 80 may optionally be disposed in more than one surfaceand in various combinations. For example, one conductive rail may bedisposed on the bottom interior surface of a file drawer, while anotherconductive rail may be disposed on an interior side surface of the filedrawer. Further, one conductive rail may be disposed on the side orbottom of a file drawer and another conductive rail may be disposed on asupport rail, such as that shown in FIG. 7. Additionally, in a shelf orbookcase, one conductive rail could be disposed on a back surface andanother could be disposed on a top surface of a shelf.

File folders 70a, 70b preferably include conductive strips including atleast one return conductive strip 72a, 72b and a control conductivestrip 73a, 73b arranged in a pattern that allows for relative movementbetween file folders or between the file folder and a bus conductor,such as that shown in FIG. 5 or that shown in FIG. 6. The conductivestrips are preferably applied to both large exterior surfaces as well asmade to extend around the side and bottom edges. By applying theconductive strip pattern to both large exterior surfaces of file folder70a, 70b, 70c, a file folder 70a, 70b, 70c that is not in direct contactwith bus conductor 80a, 80b is nevertheless permitted to have aconnection to bus conductor 80a, 80b via adjacent and intermediate filefolders 70a, 70b, 70c. Thus, if too many file folders 70a, 70b, 70c areplaced in a file drawer 54 such that a file folder 70a, 70b, 70c islaterally shifted and cannot directly contact bus conductor 80a, 80b aconnection will be provided through adjacent file folders 70a, 70b, 70c.Similarly, file folders 70a, 70b, 70c stacked in a file tray 40 willhave a connection to bus conductor 80a, 80b via file folders 70a, 70b,70c positioned therebetween.

As shown in FIG. 5, file folder 70a has at least one large exteriorsurface having a top and bottom edge as well as left and right sideedges. The conductive strip pattern shown thereon includes threeconductive strips (i.e., conductors)--one control conductive strip 73aand two return conductive strips 72a. The control conductor 73a is "V"shaped and includes a first conductive linear strip 73a' extending fromthe left edge of the surface to a central point on the bottom edge ofthe surface and a second conductive linear strip 73a" extending from thecentral point on the bottom edge of the surface to the right edge of thesurface. A first one of the return conductors 72a includes a linearstrip 72a' extending in parallel to the first conductive linear strip73a' of the control conductor 73a from the left edge of the surface tothe bottom edge of the surface. The other one of the return conductors72a includes a linear strip 72a" extending in parallel to the secondconductive linear strip 73a" of the control conductor 73a from thebottom edge of the surface to the right edge of the surface. The linearstrips of the two return conductors 72a are positioned an equal distanceon opposite sides of the control conductor 73a. Preferably, the sameconductive strip pattern is applied to the back or other exteriorsurfaces of file folder 70a.

As shown in FIG. 6, file folder 70b also has at least one large exteriorsurface having a top and bottom edge as well as left and right sideedges. The conductive strip pattern shown thereon includes threeconductive strips--one control conductive strip 73b and two returnconductive strips 72b. The control conductor 73b consists of aconductive linear strip extending from the top edge of the surface to abottom edge. The return conductors 72b are formed of two linear strips72b' and 72b", each extending in parallel to the conductive linear stripof the control conductor 73b from the top edge to the bottom edge. Thetwo linear strips 72b', 72b" constituting the return conductors 72b arepositioned an equal distance on opposite sides of the control conductor73b. Preferably, the same conductive strip pattern is applied to theback or other exterior surfaces of file folder 70b.

The conductive strip patterns shown in FIGS. 5 and 6 permit properelectrical contact even when the file folders 70a, 70b are rotated 180°about the illustrated y axis, which parallels the left side edges of thefile folders, relative to one or more adjacent file folders or relativeto bus conductor 80a, 80b. The conductive strip pattern shown in FIG. 5may be utilized with either of the bus conductors 80a, 80b shown inFIGS. 5 and 6 because the strips overlap or extend around both thebottom and side edges of the file folder and permit proper electricalcontact even when a file folder 70a is rotated 90° about the z axis,which is orthogonal to the large exterior surfaces of file folders 70a,70b, with respect to adjacent file folders or bus conductor 80a, 80b.Further, the conductive strip pattern shown in FIG. 5 permits contactwhen laid flat on an adjacent file folder or an appropriately arrangedbus conductor.

The conductive strip pattern shown in FIG. 6 is similarly advantageousin that proper electric contact may be made regardless of whethercontact is made with the edge of file folder 70b or with the entiresurface of file folder 70b should file folder 70b be laid flat onconductive bus 80b. Thus, with respect to bus conductor 80b or anadjacent file folder, file folder 70b may be rotated 180° about the x,y, and z axes, and further may be rotated 90° about the x axis, whichparallels the bottom edges of file folders 70a, 70b, without disruptingthe electrical contact between bus conductor 80b and the conductivestrips. Additionally, the conductive strip pattern shown on file folder70b permits file folders 70b to be significantly laterally shifted inthe y direction relative to one another while still maintaining thenecessary contact.

Hence, the conductive strip patterns are configured to electricallyconnect an addressable folder switch 76 with electrical contacts of thefile tracking system when the file folder is positioned in any one ofseveral different positions that allow a proper connection to be made.Further, the conductive strip patterns are configured to electricallyconnect an addressable folder switch 76 with the file tracking systemwhen the file folder 70 is positioned in (1) any one of severaldifferent orientations with respect to the electrical contacts of theelectronic file tracking system; (2) any one of several differentlateral positions with respect to an adjacent file folder; or (3) anyone of several different rotated positions with respect to an adjacentfile folder. Additionally, the conductive strip pattern is preferablyconfigured to electrically connect the addressable folder switch 76 tothe file tracking system at a plurality of locations on the file folder70.

The conductive strips may be formed of conductive tape, fabric, coating,which may be a conductive ink or polymer, or other suitable conductivematerials. The choice between such materials being a factor of the shapeand composition of the particular file folder, cost and longevity goals,and other concerns.

As evident from the foregoing description of the bus conductors and theconductive strip patterns applied to the file folders, the file trackingsystem of the present invention offers exceptional flexibility, both indesign and in use.

Having described the preferred structure of the first embodiment of thepresent invention, the operation of file tracking system 10 will now bedescribed with reference to FIGS. 8-13.

FIG. 8 shows a main user interface window 200 that a user would see ondisplay 22 of processor 20. Main user interface window 200 indicates thetitle 201 of a file identified in the database, the content and keywordsof the file 202, the location of the file 203, the originator of thefile 204, the date the file was filed in the system 205, the name of thelast user of the file 206, the date the file was last removed from thesystem 207, and the date the file was returned to the system 208. Thedatabase may store additional information for display to the user. Forexample, the database may store the locations in a computer networkwhere any redundant copies of the file are stored.

The software utilized in file tracking system 10 generally includes auser interface module for providing windows, dialog boxes, and menus,such as window 200. Preferably, the user interface module operates in agraphic user interface such as Windows™ software available fromMicrosoft Corporation. The software also includes several standaloneevent subroutines that are executed when their associated controls areactivated by a user or for timed events, at the configured intervals.The event subroutines may be classified into four main functionalgroups: a database interface; a bus interface; option control; and Debugcontrol.

The database interface subroutines provide the viewing, editing, andsearch capability for the file folder records. The viewing controlsallow movement through the database records and the display of recordfields. The editing controls allows the entry, deletion, and updating ofdatabase records. The search controls let the user locate records byvalue within the title or content keyword field, and the viewing of thesearched group.

The bus interface subroutines compile and issue control signals over bus30 to the various branch control point switch assemblies 93 and filefolders 70 on the system. An example of an interface for a single pairbus having addressable switches 100 connected thereto is TMEX™ interfaceavailable from Dallas Semiconductor, Dallas, Tex. Preferably, the businterface includes functions to start and stop a communication session,identify attached devices, and the sense and control the functioning ofthe addressable switches.

The option control subroutines allow the user to adjust the indicatorlight blink rate, the indicator light ON duration, bus scan rate, devicepersistence, and form display to include debug information. A user mayset the indicator light blink rate and the bus scan rate by defining theperiod between their events, which is the interval property of theirtimer control. The user may set the device persistence in increments ofbus scan rate and controls the length time that passes before processor20 considers a missing file folder device to be removed. Thispersistence compensates for intermittent contacts during file foldermovement. The debug information includes a status window used to displayprogram messages, access to debug controls, and database fields notnormally of interest to the user such as state variables and the uniqueaddress associated with the device.

The debug controls allow the status messages to be cleared, the bus tobe reset, and the scan timers to be enabled/disabled. FIG. 9 shows adebug window 210 illustrating the manner in which the user interfacepresents the debug controls to a user.

The operations described below, utilize various combinations of theevent subroutines described above. Thus, any given operation may includeone or more data interface subroutine, bus interface subroutine, optioncontrol subroutine, and/or debug control subroutine.

FIG. 10 shows a polling rate request window 215, which allows a user toadjust the rate at which file tracking system 10 polls the file folderslocated within the system. A user may display the polling rate requestwindow 215 by selecting the "Options" menu on main user interface window200.

With the exception of the ability to adjust the polling rate, processor20 generally polls file folders 70 and maintains the databasetransparently to the users. The manner by which processor 20periodically polls file folders 70 will be described with reference tothe flow charts shown in FIGS. 11 and 12.

Polling (Step 300) occurs periodically at the rate established by theuser in polling rate request window 215. Initially, processor 20executes a scan of a main branch looking for new, reconnected, andremoved branch control point switch assemblies 93 (Step 302). The mannerby which processor 20 performs this operation is shown in the flow chartin FIG. 12.

Processor 20 initiates a scan 302, 330 by opening communication with thedesired main branch 98 (FIG. 2) (Step 304). Then processor 20 attemptsto detect the presence of a device (in this case a branch controlleraddressable switch) (Step 306). By a process of elimination, processor20 may determine the unique address of any newly detected branchcontroller addressable switch 94 and store the unique address in thedatabase. If a branch controller addressable switch 94 is found,processor 20 queries whether branch controller addressable switch 94 isnew by accessing the database and determining whether a branchcontroller addressable switch 94 having the received unique address waspreviously registered therein (Step 308). If the branch controlleraddressable switch 94 detected is new, processor 20 adds the branchcontroller addressable switch 94 to the database and automatically fillsin whatever fields can be filled in with the information that may beobtained such as the location of branch controller addressable switch 94(Step 310).

To determine the unique address of devices, such as addressable folderswitches 76 and branch controller addressable switches 94, located on agiven branch, processor 20 issues a command instructing the addressablefolder switches 76 and branch controller addressable switches 94 totransmit the unique address stored in ROM 108 bit by bit. When aplurality of devices are present on the activated branch, each of themsimultaneously transmits the first bit of the unique address on bus 30.Processor 20 senses the state of bus 30, which represents a logical ANDof all the first bits of each device located on the activated bus.Processor 20 then issues a command to each device to transmit thecomplement of the first bit of their respective unique address. Ifprocessor 20 detects two "0's" in response to these two inquires,processor 20 determines that there are devices located on the branchthat have a "0" in the first bit position and other devices having a "1"in the first bit position. If all devices had a "0" in the first bitposition, the reading would have been a "0" followed by a "1". If a "1"followed by a "0" were received, processor 20 determines that all thepresent devices have a "1" in the first bit position. Last, if processor20 detects two "1's", no devices are present on the activated branch.

The above procedure for identifying unknown devices on a branch may befurther optimized by first disabling all known devices on the branch andthen performing the operation on those devices that are not disabled. Inthe illustrated embodiment, such procedure is carried out using theSearchROM command included with the TMEX Software from DallasSemiconductor.

Processor 20 then issues a control signal including one of the "1" or"0" logic values in the first bit position in order to disable thedevices that do not have this logic value in the first bit position oftheir unique address. Processor 20 then issues a command to the devicesthat remain enabled requesting these devices to transmit the second bitof their unique addresses and the complement thereof. Processor 20 thenuses the same process to determine the value of the second bit of atleast one of the remaining devices. Processor 20 repeats the above stepsuntil the unique address of one of the devices is known.

Subsequently, processor 20 reactivates the other devices on theactivated branch and repeats the above process using a different logiclevel at the highest bit position where processor 20 was able todetermine that a single device remained. In this manner, processor 20determines the unique address of each file folder 70 and branchcontroller 93 located on an activated branch.

After the new branch controller addressable switch 94 has been added tothe database, processor 20 scans the rest of main branch 98 looking foradditional branch controller addressable switches 94 (Step 306). Ifprocessor 20 detects a branch controller addressable switch 94 on themain branch 98 that is not new, processor 20 compares the branchcontroller state and location with that previously stored in thedatabase and updates the database if any changes are detected (Step312). Processor 20 continues to search for additional branch controlleraddressable switches 94 on main branch 98 until no further branchcontroller addressable switches 94 are detected in Step 306.

When processor 20 determines that no further branch controlleraddressable switches 94 are present on main branch 98, processor 20closes communication with main branch 98 (Step 314). Next, processor 20queries the database for the number of branch controller addressableswitches 94 presently registered in the database as being located onmain branch 98 (Step 315) and compares this number with the number ofbranch controller addressable switches 94 that processor 20 detected inStep 306 while scanning main branch 98 (Step 316). If the number ofbranch controller addressable switches 94 presently registered exceedsthe number of branch controller addressable switches 94 detected,processor 20 determines that at least one branch controller addressableswitch 94 has been removed from main branch 98.

To verify that a branch controller addressable switch 94 has beenremoved, processor 20 reopens communication with main branch 98 (Step318) and transmits control signals to each branch controller addressableswitch 94 registered in the database by including the unique addressthereof in the control signal, which is stored in the database (Step320). If a branch controller addressable switch 94 fails to respond tothe control signal sent by processor 20, processor 20 changes the stateof the branch controller addressable switch 94 registered in thedatabase to "timing out" (Step 322). After processor 20 transmits acontrol signal to each registered branch controller addressable switch94, processor 20 closes communication with main branch 98 (Step (324).

After processor 20 has closed communication with the reopened mainbranch 98 in Step 324 or after processor 20 has determined that thenumber of branch controller addressable switches 94 registered in thedatabase does not exceed the number of branch controller addressableswitches 94 detected in Step 316, processor 20 queries the database forthe identity and unique address of all present branch controlleraddressable switches 94 on the main branch 98 (Step 326 in FIG. 11) andchanges the state of addressable branch controller switches 94 toconducting one at a time in order to activate each secondary branch 99(Step 328).

While a branch controller addressable switch 94 is conducting, processor20 scans the activated branch for new, replaced, or removed file folders70 contacting the activated branch (Step 330). The manner by whichprocessor 20 performs this operation is shown in the flow chart in FIG.12.

First, processor 20 opens communication with the desired secondarybranch 99 (Step 304). Then processor 20 attempts to detect the presenceof a device (in this case a file folder 70) (Step 306). If a file folder70 is found, processor 20 queries whether file folder 70 is new byaccessing the database and determining whether file folder 70 waspreviously registered therein (Step 308). If the file folder 70 detectedis new, processor 20 adds file folder 70 to the database andautomatically fills in whatever fields can be filled in with theinformation that may be obtained (Step 310). By the process ofelimination, processor 20 may determine the unique address of any newlydetected addressable file folder switch 76 and store the unique addressin the database. After the new file folder 70 has been added to thedatabase, processor 20 scans the rest of the opened secondary branch 99looking for additional file folders 70 (Step 306).

If processor 20 detects a file folder 70 on the opened secondary branch99 that is not new, processor 20 compares the file folder state andlocation with that previously stored in the database and updates thedatabase if any changes are detected (Step 312). Processor 20 continuesto search for additional file folders 70 on secondary branch 99 until nofurther file folders 70 are detected in Step 306.

When processor 20 determines that no further file folders 70 are presenton the opened secondary branch 99, processor 20 closes communicationwith this secondary branch 99 (Step 314). Next, processor 20 queries thedatabase for the number of file folders 70 presently registered in thedatabase as being located on this secondary branch 99 and compares thisnumber with the number of file folders 70 that processor 20 detected inStep 306 while scanning the secondary branch 99 (Step 316). If thenumber of file folders 70 presently registered exceeds the number offile folders 70 detected, processor 20 determines that at least one filefolder 70 has been removed from the opened secondary branch 99.

To verify that a file folder 70 has been removed, processor 20 reopenscommunication with the secondary branch 99 (Step 318) and transmitscontrol signals to each file folder 70 registered in the database byincluding the unique address thereof in the control signal, which isstored in the database (Step 320). If a file folder 70 fails to respondto the control signal sent by processor 20, processor 20 changes thestate of the file folder 70 registered in the database to "timing out"(Step 322). After processor 20 transmits a control signal to eachregistered file folder 70, processor 20 closes communication with thissecondary branch 99 (Step (324).

After processor 20 has closed communication with the reopened secondarybranch 99 in Step 324 or after processor 20 has determined that thenumber of file folders 70 registered in the database does not exceed thenumber of file folders 70 detected in Step 316, processor 20 activatesanother secondary branch 99 by transmitting a control signal includingthe unique address of the branch controller addressable switch 94associated with the selected secondary branch 99 (Step 328 in FIG. 11).

After processor 20 has scanned all the secondary branches 99, processor20 queries the database for the identity of all devices in the "timingout" state (Step 332) and decrements the persistence values stored inassociation therewith (Step 334). The persistence value indicates thenumber of additional times that processor 20 will perform a scan of allfile folders 70 before a file folder having a "timing out" status willbe considered to have a "timed out" or removed status. When a filefolder has "timed out" (Step 336), processor 20 updates the database toindicate this change in status (Step 338) and ends the scanningoperation (Step 340). Once the scanning operation is finished, a timeris started to determine when the next scanning operation is to beperformed.

Processor 20 automatically updates the database by inserting the dateand time the file was detected as having been removed from the systeminto the appropriate database fields associated with file folder 70.Additionally, processor 20 may identify the individual who removed filefolder 70 by determining who was the last individual to log onto thesystem and cause the indicator light of the removed file folder toblink. This is especially helpful in locations where security measuresrequire logging onto the system before removing files. Then, if thepresence of the removed file folder 70 is subsequently detected at adifferent location, such as on an individual's desk, processor 20 mayupdate the database to indicate that the individual who removed the fileis the individual associated with the location (i.e., desk) where filefolder 70 was subsequently detected or have a separate fieldcorresponding to the individual responsible for that particular area orlocation.

By actively polling each file folder 70, file tracking system 10maintains an accurate record of file folder location and usage historywithout requiring action by office personnel. Moreover, office personnelneed not spend their valuable time keeping the files organized. Usingfile tracking system 10, a person may quickly determine the presentlocation of a file folder and cause LEDs on the file folder and filecabinet drawer to blink to allow the person to quickly identify therequested file folder. Because of the ease by which a person may locatea file folder, office personnel may place the file folders anywhere andin any convenient order. Thus, office personnel may place the mostfrequently used file folders at the front of a file drawer where theyare more easily accessed at a later time. Furthermore, because new filefolders may be placed in any file drawer or on any shelf, there is noneed to rearrange the file folders to make room for new file folders.

In addition, by utilizing a database to index file folders, the filefolders may be physically grouped or classified into various topicalgroups and subgroups. Thus, a user may access all the file foldersconstituting the group or subgroup. Moreover, by issuing an appropriatecommand, a user can cause the indicator lights on all the file foldersof a selected group of file folders to blink thereby adding to the easeby which the user can locate the physical file copies for immediate useor to gather for placement into a desired storage pattern or location.Similarly, a user can locate all files mentioning a particular subjectby performing a keyword search. Thus, the present invention may providehigher levels of file organization even if a user wishes to maintain thefiles in a specific nonrandom order.

FIG. 13 is a flow chart illustrating the operation of file trackingsystem 10 when operating in an indicator light scanning operation. Aswill be apparent from the following description, the indicator lightscanning operation is useful for causing the indicator lights on theselected file folders and branch indicators to blink.

An indicator light scanning operation is performed at timed intervals(Step 400). Processor 20 begins the operation by querying the databasefor all present branch controller addressable switches 94 on the mainbranch (Step 402). Then, for each branch controller addressable switch94 that is present (Step 404), processor 20 queries the database forfile folders 70 having an indicator light blink flag set to logic "1"and located on the branch controlled by the selected branch controlleraddressable switch 94 (Step 406). The indicator light blink flag for afile folder is set when a user requests processor 20 to blink theindicator light of a selected file folder. If no file folders are foundthat are connected to the selected branch (Step 408) and have theirindicator light blink flag set to "1", processor 20 selects the nextbranch (Step 404). If the processor 20 finds file folders 70, processor20 queries the database for branch indicators on the selected branch(Step 410), then processor 20 opens communication with the selectedbranch (Step 412) and transmits control signals to each branch indicator95 that is found on the selected branch (Step 414) causing the branchindicator lights 96 to toggle on and off (Step 416). Next, processor 20transmits control signals to each file folder 70 that is found on theselected branch having its indicator light blink flag set to "1" (Step418) causing the folder indicator lights 75 to toggle on and off (Step420). After all of the folder indicator lights 75 on the selected branchhave been toggled, processor 20 closes the selected branch (Step 422)and selects the next branch (Step 404). The process is repeated untilthere are no more branches to select (Step 424). This procedure may beprogrammed to be executed several times per second.

The control signals transmitted by processor 20 to toggle the indicatorlights may include a first control signal containing the unique addressof the addressable device followed by a second transmitted controlsignal including a command to toggle the indicator light. Alternatively,the control signals may include a single control signal transmitted byprocessor 20 that includes both the unique address and the command totoggle the indicator light.

Although the above procedure is presently used to blink the indicatorlights, it is also possible to utilize indicator lights that blink uponreceiving an instruction to do so until a subsequent instruction isreceived to stop blinking. Further, processor 20 may read each indicatorfor the status of the indicator light prior to issuing a control signalcausing the indicator light to blink in order to ensure that theindicator light is not already turned on.

FIG. 14 shows a file tracking system 500 constructed in accordance witha second embodiment of the present invention.

The second embodiment of the file tracking system 500 differs from thefirst embodiment only in that file tracking system 500 includes aplurality of processors 20a-20d interconnected by a network, such as alocal area network (LAN) 91 or a local office network (LON). An exampleof a LON in which the present invention may be implemented is disclosedin U.S. patent application Ser. No. 08/165,029, the disclosure of whichis incorporated by reference herein. Each processor may store a portionof the entire database of the system such that the various processorsand their respective portions of the database constitute a distributeddatabase system 501. In such a system any one of processors 20a-d mayaccess the database stored in any other processor using a conventionaldistributed database management system (DDBMS), a networked databaseserver, or through database information stored with the file folder.

The DDBMS architecture of tracking system 500 allows any single filetracking program to operate on records that are spread across multipledatabases that are running on a variety of different processors andoperating systems connected through a variety of communication networks.In a networked database server, a single processor maintains a centraldatabase with the other processors having a subset copy of the recordspertaining to the file folders local to each processor. A processorwould use this local copy to monitor the file folder state and indicatorlight state, and relay only changes in state back to the centraldatabase.

By scaling the file tracking system of the present invention to permitmultiple access to the system at various locations, file tracking system500 permits multiple users in various locations to locate file foldersthat are in distributed locations about the organization. Thus, thissystem can easily be adapted for use in a large organization havingnumerous office buildings in which file folders may be located in anyoffice or file repository of these office buildings.

Although the above embodiments of the present invention have beendescribed as using physical connections between the various elements,any one or all of the above connections may be replaced with a radiolink by providing a radio frequency (RF) transceiver connected toprocessor 20 and RF transceivers on the folder retainers and/or the filefolders themselves. FIG. 15 shows a third embodiment using RF signals.The third embodiment differs from the second embodiment in that RFtransceivers 120 are connected to processor 20 and either to each filefolder 70 or to each folder retainer, which refers to tray 40, filecabinet 50, shelving unit 60, and desk drawer 86. The third embodimentmay utilize the same RF communication protocols as used in cellulartelephones. For example, the system may employ cellular digital packetprotocol (CDPP) or the protocol used for personal communication systems(PCS). These protocols may be employed by utilizing branch controllersas a cell base station whereby file folders located within each cellregister with the closest cell base station such that processor 20 maytrack the location of each file folder.

Although the embodiment shown illustrates a system utilizing all RFlinks from processor 20, a combination of RF links and physical busconnections may also be employed. By providing the availability of radiolinks, mobile folder retainers, such as file carts, as well as remotelylocated folder retainers may be employed in the file tracking system ofthe present invention.

Although the processor(s) of the present invention have been describedwith reference to personal computers, the processor may be a processorembedded in or near the folder retainer. In such an arrangement, it maybe preferable for the embedded processor to include a plurality ofserial ports to which different branches of the bus may be connected,thus, eliminating the need for a number of branch controllers. Further,the processors may be computer terminals connected to a network.

Further, processor 20 may be implemented in either a single processingunit or in a distributed system whereby various tasks performed byprocessor 20 are allocated to various components of the distributedsystem. For example, one component may be responsible for scanning thebus, while another may be used to provide an interface with the users.Further, various tasks described above as being performed by processor20 may be allocated to embedded processor 27. For example, embeddedprocessor 27 may maintain separate databases identifying which filefolders are located on their associated branch.

Additionally, other types of annunciators or, as more broadly definedherein, file locating devices, such as an audible alarm, may supplementor replace the visual indicator lights used in the file tracking system.

Although it is preferable that the present invention be practiced usingaddressable devices that each have a unique addresses associatedtherewith, it is possible that in a system employing a large number ofaddressable devices, two or more addressable devices could have the sameaddress. The present claims are intended to cover the situation where atleast a plurality of addressable devices have unique addresses. Toensure such coverage, some claims below recite that the addressabledevices have a substantially unique address.

The foregoing description of preferred embodiments of the invention hasbeen presented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed, and modifications and variations are possible in light of theabove teachings or may be acquired from practice of the invention. Theembodiments were chosen and described in order to explain the principlesof the invention and its practical application to enable one skilled inthe art to utilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. It isintended that the scope of the invention be defined by the claimsappended hereto, and their equivalents.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A file tracking systemcomprising:a database for maintaining file location and unique fileaddresses for a plurality of files; a processor for interfacing withsaid database and issuing control signals; a bus connected to saidprocessor; a folder retainer connected to said processor by said bus; aplurality of file folders, each file folder including an addressabledevice adapted to be electrically connected to said bus when the filefolder is placed in said folder retainer, each addressable device beingresponsive to a control signal including the unique address associatedwith the addressable device to transmit a signal back to said processorso that said processor may maintain the file location of each file insaid database wherein each of said file folders further include: asurface; a first conductor on said surface for providing control signalsto said addressable device when the file folder is placed in said folderretainer; and a second conductor on said surface for providing a groundto said addressable device, wherein said first and second conductors arestrips of conductive tape provided on said surface of the file folders.2. A file tracking system comprising:a database for maintaining filefolder information including file location, and a unique address of eachfile; a processor for interfacing with said database and issuing controlsignals; and a plurality of file folders, each file folder including anaddressable switch and an indicator, said indicator is activated whensaid addressable switch receives a control signal from said processorincluding the unique address corresponding to the file folder, whereinsaid processor is adapted to periodically poll said file folders toobtain information from each file folder, detect differences between theobtained information and the file folder information stored in saiddatabase, and to update said database when said processor detects adifference between the file folder information stored in said databaseand the polled information.
 3. The file tracking system of claim 2,wherein said processor detects when file folders have been removed,added, moved, and returned within the system.
 4. The file trackingsystem of claim 3, wherein said processor detects the location of thefile folders and determines that a file folder has been moved when thefile folder has a detected location that is different from the locationpreviously stored in said database.
 5. The file tracking system of claim3, wherein said processor detects the presence of the file folders bydetermining the unique address stored in said addressable switches ofeach file folder and determines that a new file folder has been added tothe system when the new file folder has a unique address that was notpreviously stored in said database.
 6. The file tracking system of claim5, wherein said processor automatically creates a database entry for thenew file folder, inserts the detected unique address associatedtherewith into an address field, and inserts the location at which thenew file folder was detected into a location field in said database. 7.The file tracking system of claim 3, wherein said processor detects thepresence of the file folders by determining the unique address stored inthe addressable switches of each file folder and determines that a filefolder has been removed when the file folder had a particular locationstored in said database and said processor determines that the filefolder is no longer present at that location.
 8. The file trackingsystem of claim 7, wherein said processor automatically updates saiddatabase to indicate that the removed file folder was removed, a timeand date that the filed folder was removed, and an identity of anindividual who removed the file folder.
 9. The file tracking system ofclaim 8, wherein said processor determines the identity of theindividual who removed the file folder by determining which individuallast caused an indicator light on the file folder to blink.
 10. The filetracking system of claim 8, wherein said processor determines theidentity of the individual who removed the file folder by awaiting asubsequent detection of the file folder by said processor anddetermining which individual is associated with the location in whichsaid processor detects the file folder.
 11. The file tracking system ofclaim 2, wherein said processor further:receives a reply signal from thepolled file folder, which was transmitted in response to a controlsignal transmitted by said processor to the polled file folder, thereply signal including the unique address corresponding to the polledfile folder; verifies the file location in the database corresponding tothe unique address of the polled file folder received in the replysignal; and updates the database to indicate a new file location for thepolled file folder when the location from which the reply signal wastransmitted is different from the file location previously stored in thedatabase.
 12. In a file tracking system including a processor and aplurality of files each having a unique identification code associatedtherewith and communicatively connected to the processor, a method ofmaintaining a database including file location, and the identificationcode of each of the plurality of files, the method comprising the stepsof:periodically polling each of the plurality of files by transmitting acontrol signal from the processor to a file to be polled; determiningthe identification code corresponding to the polled file from the polledfile to the processor when the polled file detects the control signal;verifying the file location in the database corresponding to theidentification code of the polled file received in the reply signal; andupdating the database to indicate a new file location for the polledfile when the location from which the reply signal was transmitted isdifferent from the file location previously stored in the database. 13.The method of claim 12, further including the steps of:determining whichfiles are missing and which files are new by comparing theidentification codes included in the reply signals with those stored inthe database; and updating the database to indicate the presence, filelocation, and identification code of a new file when the identificationcode received in a reply signal does not correspond to an identificationcode previously stored in the database.
 14. The method of claim 12,further including the steps of:determining which files are missing andwhich files are new by comparing the identification codes included inthe reply signals with those stored in the database; transmitting acontrol signal including the identification code of a missing file thatis identified in the database but which did not transmit a reply signalduring polling; and updating the database to indicate that the filelocation of a missing file is not known when the missing file does notrespond within a predetermined time period to the control signalincluding the identification code of the missing file.
 15. The method ofclaim 12, wherein the file tracking system further includes a pluralityof folder retainers each having a unique identification code, and thestep of periodically polling each of the plurality of files comprisesthe substeps of:transmitting a control signal including a uniqueidentification code of a first one of the folder retainers to enablecommunication with the files located in the first one of the folderretainers; polling each of the files located in the first one of thefolder retainers; recording as the file location of each respondingfile, the location and identity of the first one of the folderretainers; and sequentially transmitting control signals to each of theremaining folder retainers to enable the files stored therein to beseparately polled and to enable the recordation of the file location ofeach responding file.
 16. The file tracking system of claim 12, whereinthe control signal transmitted from said processor to the file to bepolled is sent over a conductor that is communicatively coupled to morethan one file to be polled, and the unique identification codecorresponding to the polled file is determined based upon informationtransmitted from the polled file to said processor in response to thecontrol signal.
 17. A file tracking system comprising:a database formaintaining file location and unique file addresses for a plurality offiles; a processor for interfacing with said database to obtain theunique file address of a specified file, and for issuing a controlsignal including the unique file address obtained from said database forthe specified file; a bus connected to said processor; a folder retainerconnected to said processor by said bus; and a plurality of filefolders, each file folder including an addressable device adapted to beelectrically connected to said bus when the file folder is placed insaid folder retainer, each addressable device being responsive to theunique address associated with the file contained within thecorresponding file folder that is included in a control signal receivedfrom said processor.
 18. The file tracking system of claim 17 andfurther including a plurality of folder retainers connected to saidprocessor by said bus and remotely located relative to a memory devicein which said database is stored, wherein the file location stored insaid database for each of said plurality of files corresponds to thefolder retainer in which the corresponding file folder is located.
 19. Afile tracking system comprising:a database for maintaining file locationand unique file addresses for a plurality of files, said databasefurther maintains user identification data for a plurality of filesindicating which user last accessed the file; a processor forinterfacing with said database and issuing control signals; a busconnected to said processor; a folder retainer connected to saidprocessor by said bus; and a plurality of file folders, each file folderincluding an addressable device adapted to be electrically connected tosaid bus when the file folder is placed in said folder retainer.
 20. Thefile tracking system of claim 19, wherein said processor determines thata file folder was removed from its last location by sending andreceiving signals from said file folders over said bus and comparinginformation in a received signal to information stored in said database,and said processor automatically updates said database to indicate thatthe removed file folder was removed and an identity of an individual whoremoved the file folder.